An Etymological Dictionary of Astronomy and Astrophysics

A fundamental system for the classification of → asteroids based on → albedo and → spectral characteristics. The Tholen scheme includes 14 types with the majority of asteroids falling into one of three broad categories, and several smaller types.
→ C-type asteroid, → M-type asteroid, → S-type asteroid.

See also: David J. Tholen (1984) Ph.D. thesis, University of Arizona; → classification.